Re: [PATCH] drm/i915/vbt: Assume port A is connected to eDP when there's no VBT

From: Manasi Navare <manasi.d.navare@intel.com>
To: Jani Nikula <jani.nikula@intel.com>
Cc: Dhinakaran Pandiyan <dhnkrn@gmail.com>,
	"Vivi, Rodrigo" <rodrigo.vivi@intel.com>,
	"intel-gfx@lists.freedesktop.org"
	<intel-gfx@lists.freedesktop.org>,
	"Pandiyan, Dhinakaran" <dhinakaran.pandiyan@intel.com>
Subject: Re: [PATCH] drm/i915/vbt: Assume port A is connected to eDP	when there's no VBT
Date: Thu, 10 Aug 2017 09:17:10 -0700	[thread overview]
Message-ID: <20170810161710.GA584@intel.com> (raw)
In-Reply-To: <87poc3sc7f.fsf@intel.com>

On Thu, Aug 10, 2017 at 05:56:52PM +0300, Jani Nikula wrote:
> On Thu, 10 Aug 2017, "Navare, Manasi D" <manasi.d.navare@intel.com> wrote:
> > We currently assume port A is connected to a DP sink when VBT is absent, instead assume it is connected to an eDP sink, which seems like a more common configuration. Although I don't have data to back this up, it is still just as valid as asumming port A is not eDP. This reverts to the behavior before a98d9c1 ("drm/i915/ddi: Rely on VBT DDI port info for eDP detection") except only when there is no VBT. Knowing whether a panel is eDP or not from the panel itself would have been nicer, but I cannot find any DPCD registers that provide this reliably.
> >
> > Cc: Jani Nikula <jani.nikula@intel.com>
> > Cc: Imre Deak <imre.deak@intel.com>
> > Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
> > Cc: Clint Taylor <clinton.a.taylor@intel.com>
> >
> > Signed-off-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>
> >
> > Is this patch trying to fix a specific bug? Where do you plan to use supports_edp flag? 
> > I guess I am trying to understand the need for this in the vbt missing defaults and what this patch is trying to solve here. 
> 
> Hate to be a nag, but your reply quoting is broken again. So much so
> that patchwork tripped over [1]. Please try to get it fixed.
> 
> BR,
> Jani.
> 
>

Yea I am sorry I knew it would mess up the formatting. For some reason I was having issues
connecting to the server with mutt so had to reply using Outlook and that probably
messed it up really bad. But with my mutt client its usually fine.

Regards
Manasi

> [1] https://patchwork.freedesktop.org/series/28597/
> 
> 
> >
> > Manasi
> >
> >
> > ---
> >  drivers/gpu/drm/i915/intel_bios.c | 1 +
> >  1 file changed, 1 insertion(+)
> >
> > diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c
> > index 82b144c..89a405e 100644
> > --- a/drivers/gpu/drm/i915/intel_bios.c
> > +++ b/drivers/gpu/drm/i915/intel_bios.c
> > @@ -1403,6 +1403,7 @@ init_vbt_missing_defaults(struct drm_i915_private *dev_priv)
> >  		info->supports_dvi = (port != PORT_A && port != PORT_E);
> >  		info->supports_hdmi = info->supports_dvi;
> >  		info->supports_dp = (port != PORT_E);
> > +		info->supports_edp = (port == PORT_A);
> >
> >  	}
> >  }
> >  
> > --
> > 2.7.4
> >
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx@lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx@lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
> 
> -- 
> Jani Nikula, Intel Open Source Technology Center
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